2014 * XXV * 1

Summary of trial results of reed canarygrass (Phalaris arundinacea L.) seed production that were conducted at JõgevaA. Bender Reed canarygrass (Phalaris arundinacea L.) is a naturally widespread grass in Estonia, which so far has successfully been used as a dominant species in the stands of cultural meadows on reclaimed alluvial and peat soils. Because of high and stable dry matter yield through years, in the past decades the species has been started to be used in addition to fodder production also as raw material for cellulose and energy pro-duction. Compared to other grasses, reed canarygrass is characterized by a moderate and unstable seed yield. In the years 2008–2013 a number of experiments was conducted at the Jõgeva Plant Breeding Institute in order to investigate the effect of seeding rate (4, 6, 8, 10 kg ha-1), row spacing (15, 30, 45, 60 cm), nitrogen fertilizer rate (N 70, 105, 140 kg ha-1) and cutting time of stubble hay (July, October, April) on the seed yield of reed canarygrass. The trial results indicated that when the seed field was established with narrow spacing (15 cm), seeding rate of 4–6 kg ha-1 and nitrogen was applied at the rate of N 140 kg ha-1, the reed canarygrass "Pedja" yielded in the first two years of use up to 430 kg of seed per hectare. In the following years of use the seed yield dropped drastically. It was expedient to cut the stubble hay at the end of the vegetation period (October) or even next spring (April). Besides the seed yield, it was possible to harvest from the trials 5–8 t ha-1 of dry matter the energetic value of which was 140 GJ. The moisture content of straw harvested in July was 14.5–20.3%, of stubble hay harvested in April 14.3–15.2%. The straw of reed canarygrass as well as the stubble hay harvested in April can be used as energy hay, the sales revenue of which made 12% of the total estimated sales revenue. Keywords: reed canarygrass, seeding rate, row spacing, nitrogen fertilizer, harvest time of stubble hay, seed yield, biofuel Allikas: Agraarteadus 2014 (25) 1:3-16

Phenology and formation of local population of Colorado potato beetles in 2008–2013 (Leptinotarsa decemlineata Say)K. Hiiesaar, V. Eremeev, L. Metspalu, E. Kruus, A. Luik In the long term five field crop rotation experiments of organic and conventional growing systems on potato plots the phenology and formation of local-population of Colorado potato beetles were monitored from 2008 to 2013. The beetles started to colonize the field from the establishment of the experiment. The initial population density of beetles was low in both, conventional and organic plots because various cereals and rape had been cultivated on the field and in the vicinity for many years previously. The number of beetles and damage level increased year after year because the potato field remained at the same block, the suitable overwintering places were nearby and the winter mortality was low. As a result of coincidence of several favourable factors like constantly high temperatures, optimal precipitation and availability of fresh food until the late autumn, the second generation of beetles developed in 2010 in Estonia for the first time. This year the number of pest increased sharply when the summer beetle’s offspring reach the adult stage and started to reproduce. The unprotected plots were entirely defoliated, in the conventional plots application of Fastac 50 killed the larvae and therefore the plants had less damage. As the spraying did not destroy the adults and the eggs, the new larvae hatched soon. Early spring and warm summer promoted fast emergence of beetles and enabled development of two generation also in 2013 for the second time. During the observation period the numerous vital local Colorado potato beetles population has been developed in this area. This was facilitated by the neighbouring position of organic and conventional plots as the organic plot acted as a reservoir of the pest and the conventional plot as a food reserve.Keywords: generation, degree day, conventional, organic, mass of beetles, population density, potato plots, precipitatio Allikas: Agraarteadus 2014 (25) 1:17-22

http://agrt.emu.ee/pdf/2014_1_hiiesaar.pdf

Eesti Maaülikool, Põllumajandus- ja keskkonnainstituut

H. Kaldmäe, A. Olt, R. Leming, M. Ots

Rohu- ja maisisilode mükotoksiinidega saastatus Eestis

23

Mycotoxin contamination in grass and maize silage in EstoniaH. Kaldmäe, A. Olt, R. Leming, M. OtsThe silage quality estimated by chemical composition and fermentation parameters, but awareness of the composition of mycotoxins is of great importance. The aim of this study was to determine the concentration of the mycotoxins (deoxinivalenol (DON) and zearalenon (ZEA)) in silage produced on Estonian farms (n=56), in the years 2011, 2012 and 2013. A total of 596 grass, 55 maize and 10 whole-crop silage samples were collected for analyses. The silages were found to contain mycotoxins. In grass silage, 92% of samples were found to be positive for DON and 100% for ZEA, while in maize silage samples 95.7% were positive for DON and 100% for ZEA in 2013. The mean concentration of DON of grass silage was 209 ppb while the concentration of ZEA was 329 ppb. In maize silage the mean concentrations of DON and ZEA were 227 ppb and 292 ppb respectively. ZEA concentration in first-cut grass silage was a mean of 257.4 ppb, the second cut 245.0 ppb and the third cut 224.4 ppb, while the figures for DON concentrations were 214.7 ppb, 190.8 ppb and 166.3 ppb respectively. Silage with a dry matter content of <25% contained fewer of the analysed mycotoxins compared to silages with dry matters of 35–45%. During the growing period grass forage was contaminated with mycotoxins, most of all by DON and ZEA. Mycotoxin concentrations increased in the field before the forage was cut for silage making. The ZEA and DON concentrations increased by with increased growth time of the forage. The maximum levels of mycotoxin contents of the grass were recorded at the time of harvest. DON and ZEA concentrations in the summer period depended on the grass species and the weather conditions.Keywords: grass silage, maize silage, deoxynivalenol, zearalenone, mycotoxins Allikas: Agraarteadus 2014 (25) 1:23-29

"Year 2014 soil" − the leached soilR. Kõlli, I. TammBy Estonian Soil Sciences Society for the year 2014 soil the leached soils as one of the best arable soils of Estonia was elected. After WRB these soils embrace mainly Haplic & Endogleyic Cambisols (calcaric, endoskeletic). The area of leached soils forms 7.7% from whole Estonian soil cover or a little bit more than 3250 km2. In overview on Estonian year 2014 soil the morphology, genesis, classification, humus status and different properties (chemical, physical, hydro-physical) are treated on detail level of Estonian Soil Classification, for which are soil species (identified by soil genesis) and soil varieties (divided on the basis of soil texture). Besides abovementioned characteristics the productivity, environment protection ability in dependence upon soil functioning and properties, usage in agriculture and forestry, and distribution in Estonia of leached soils is analysed.Keywords: leached soils, year 2014 soil, cambisols, soil properties Allikas: Agraarteadus 2014 (25) 1:30-38

Meat oxidation - mechanisms and influence on quality and safety of meat productsT. PüssaMeat is a foodstuff liable to (per)oxidation by different mechanisms including free radical and enzyme-catalyzed processes. Meat oxidation starts with lipids and heme and continues also with proteins. Oxidation that produces different undesirable chemical substances, such as leukotoxin diols, aldehydes, carbonylated amino acids, has significant influence on various quality and safety parameters of meat. Meat oxidation is favored by shortage of antioxidants in feed, high content of PUFAs and high comminution rate of meat, heat and light during processing, high pressure processing etc. Meat oxidation can be reduced by antioxidant supplements in feed and during processing, low temperatures, special packagings etc. Keywords: meat, (per)oxidation, mechanisms, products, quality and safety, prevention Allikas: Agraarteadus 2014 (25) 1:39-47